A shape descriptors comparison for organs deformation sequence characterization in MRI sequences

A quantiative approach for the assessment of the pelvic dynamics modeling

“…Several sd have been experimented, such as the shape signature, the Zernike moments, or the Fourier descriptors. We have shown in [7] that the results of different descriptors are equivalent. We used Fourier descriptors (fd) in this study.…”

“…sd are numerical attributes representing the shape aspect, they are widely used in pattern recognition, a review is proposed in [6]. An adaptation of sd was proposed in [7]: the organ deformation at a given time is represented by the distance between the organ sd coefficients at that time, and the organ sd coefficients at the rest-state (t = 0). Several sd have been experimented, such as the shape signature, the Zernike moments, or the Fourier descriptors.…”

Pelvic Organs Dynamic Feature Analysis for MRI Sequence Discrimination

“…Feature extraction 1) Extraction of deformation features: Shape descriptors are widely used in pattern recognition and indexing, a review is proposed in [3]. We detailed the shape descriptors used in [2]. Among the space domain-based descriptors, we have chosen the shape signature, it sums up the radius variations between the shape barycenter and the boundary points.…”

“…We have developed a methodology which approximates these references from organ contours (see [2]). The anorectal angle is the junction of the rectum with the anus, we have computed this angle by exploiting the curvature properties of the rectum medial axis.…”

“…Validating the model amounts to compare the simulation results to the dynamic MRI which represents the ground truth. For this purpose, we have established elements of the pelvic organ behaviour characterization [2], those elements are based on organs deformation quantification along a sequence by using shape descriptors. The aim of our study is to estimate the deformation features relevance against usual features used by radiologists like the tracking of anatomical references which is subject to inter-operator variability.…”